Blade allows you to export JMS files from Blender for use with Halo Editing Kit. Bones and markers are unsupported at the moment so this is only really good for scenery and BSPs. It is untested beyond a basic box level so hopefully some artists here can help me iron out any bugs. After static geometry is proven to work, I can hopefully build this out to serve as a fully-featured, viable alternative to Max 8 + Blitzkrieg.